CN1648647A - Method for measuring polyisobutene molecular weight - Google Patents
Method for measuring polyisobutene molecular weight Download PDFInfo
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- CN1648647A CN1648647A CN 200410000951 CN200410000951A CN1648647A CN 1648647 A CN1648647 A CN 1648647A CN 200410000951 CN200410000951 CN 200410000951 CN 200410000951 A CN200410000951 A CN 200410000951A CN 1648647 A CN1648647 A CN 1648647A
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- polyisobutylene
- molecular weight
- peak area
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- carbon
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- 229920002367 Polyisobutene Polymers 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 title claims abstract description 31
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 31
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 29
- 125000000325 methylidene group Chemical group [H]C([H])=* 0.000 claims abstract description 20
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 17
- 239000003153 chemical reaction reagent Substances 0.000 claims abstract description 15
- 150000001335 aliphatic alkanes Chemical class 0.000 claims abstract description 7
- 238000012360 testing method Methods 0.000 claims abstract description 7
- 238000001228 spectrum Methods 0.000 claims description 10
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 9
- 238000005481 NMR spectroscopy Methods 0.000 claims description 8
- JNRLEMMIVRBKJE-UHFFFAOYSA-N 4,4'-Methylenebis(N,N-dimethylaniline) Chemical compound C1=CC(N(C)C)=CC=C1CC1=CC=C(N(C)C)C=C1 JNRLEMMIVRBKJE-UHFFFAOYSA-N 0.000 claims description 7
- 238000003556 assay Methods 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 5
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical group [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 claims description 4
- XEHUIDSUOAGHBW-UHFFFAOYSA-N chromium;pentane-2,4-dione Chemical group [Cr].CC(=O)CC(C)=O.CC(=O)CC(C)=O.CC(=O)CC(C)=O XEHUIDSUOAGHBW-UHFFFAOYSA-N 0.000 claims description 3
- 229920006395 saturated elastomer Polymers 0.000 claims description 3
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 claims description 2
- 229910052805 deuterium Inorganic materials 0.000 claims description 2
- CZDYPVPMEAXLPK-UHFFFAOYSA-N tetramethylsilane Chemical compound C[Si](C)(C)C CZDYPVPMEAXLPK-UHFFFAOYSA-N 0.000 claims description 2
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 claims 1
- 239000000126 substance Substances 0.000 abstract description 2
- 238000001644 13C nuclear magnetic resonance spectroscopy Methods 0.000 abstract 1
- 150000001336 alkenes Chemical class 0.000 abstract 1
- 239000011903 deuterated solvents Substances 0.000 abstract 1
- 238000000214 vapour pressure osmometry Methods 0.000 description 7
- 238000005227 gel permeation chromatography Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical compound CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 230000003078 antioxidant effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 230000005477 standard model Effects 0.000 description 2
- 125000004080 3-carboxypropanoyl group Chemical group O=C([*])C([H])([H])C([H])([H])C(O[H])=O 0.000 description 1
- 125000002777 acetyl group Chemical group [H]C([H])([H])C(*)=O 0.000 description 1
- -1 alkyl carbon Chemical compound 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 238000010538 cationic polymerization reaction Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 230000005311 nuclear magnetism Effects 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 229920000768 polyamine Polymers 0.000 description 1
- 150000004291 polyenes Chemical class 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- KZNICNPSHKQLFF-UHFFFAOYSA-N succinimide Chemical class O=C1CCC(=O)N1 KZNICNPSHKQLFF-UHFFFAOYSA-N 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
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Abstract
The method of measuring molecular weight of polyisobutene includes the following steps: 1) dissolving polyisobutene sample in deuterated solvent with internal standard substance to form polyisobutene solution and adding relaxation reagent to form tested sample; 2) testing the tested sample via 13C-nuclear magnetic resonance spectroscopy process to obtain carbon spectrogram; and 3) finding out the polymerization degree of polyisobutene with the peak area ratio between the alkane carbon area and alkene carbon area or the peak area ratio between the methylene area and the alpha-methylene area in the carbon spectrogram, and calculating molecular weight from the polymerization degree. The said measuring method has no need of preparing standard sample in measuring the number average molecular weight of polyisobutene accurately.
Description
Technical field
The present invention is a kind of assay method of polyisobutylene molecular weight, specifically, is a kind of method with nmr for the determination polyisobutylene molecular weight.
Background technology
In lubricating oil or railway grease, need to add antioxidant usually and oxidation deterioration in use takes place to prevent oil product.A kind of well behaved antioxidant commonly used is the polyisobutene succinimide compounds, and it is the condensed polymer that is generated by polyisobutylene, succinyl and polyamines polyene reaction, and wherein polyisobutenyl is from active or inactive low polyisobutylene product.
The polyisobutylene molecular weight is the important location parameter of development polyisobutylene product, and its assay method has multiple.At present, the method that is used to measure various mean molecular weight of polyisobutylene and molecular weight distribution is gel permeation chromatography (GPC).In addition, vapor-pressure osmometry (VPO) also can effectively be measured the number-average molecular weight of polyisobutylene.VPO and GPC method all need the standard model of known molecular amount, and draw corresponding standard curve.When test, need sample is dissolved in the bigger benzene solvent of toxicity, and bigger with the sample amount, generally need the sample that restrains.Said method is owing to need set up typical curve, and the test value of sample can be subjected to setting up typical curve the restriction of time institute's sample thief numerical value, and is inaccurate for the sample determination that exceeds the standard specimen molecular weight ranges.
Summary of the invention
The purpose of this invention is to provide a kind of method that adopts nmr for the determination polyisobutylene molecular weight, this method does not need standard specimen can effectively measure the molecular weight of polyisobutylene.
The assay method of polyisobutylene molecular weight provided by the invention comprises the steps:
(1) the polyisobutylene sample be dissolved in make polyisobutylene solution in the deuterated reagent that contains internal standard compound, add relaxation reagent again and make testing sample,
(2) use
13The C-nuclear magnetic resonance spectroscopy is measured testing sample, obtains carbon spectrum spectrogram,
(3) peak area ratio of the peak area of the peak area by alkane carbon district in the carbon spectrogram and olefinic carbon district peak area ratio or methylene base and α methylene is tried to achieve the degree of polymerization of polyisobutylene, calculates molecular weight by the degree of polymerization again.
The present invention adopts
13The C-nuclear magnetic resonance spectroscopy is measured the number-average molecular weight of polyisobutylene, determine the mean molecular weight of polyisobutylene sample by alkyl carbon atoms number in the comparison spectrogram and ratio with carbon number of " end group carbon " characteristic, therefore, need not prepare the number-average molecular weight that standard model can directly be measured polyisobutylene.
Description of drawings
Fig. 1 is a polyisobutylene
13The C-nmr spectrum.
Fig. 2 is a polyisobutylene
13Alkane carbon district spectrogram in the C-nmr spectrum.
Embodiment
The present invention adopts
13The number-average molecular weight of C-nmr for the determination polyisobutylene needs during mensuration that the polyisobutylene sample is dissolved in deuterated reagent and is mixed with solution, contains internal standard compound in the described deuterated reagent, so that determine the chemical shift (δ) of each group in the spectrogram.In addition, in the polyisobutylene solution of preparation, also need add relaxation reagent,, carry out quantitative measurement so that improve signal to noise ratio (S/N ratio).
Deuterated reagent described in the inventive method is selected from deuterochloroform or deuterium for benzene, preferred deuterochloroform.The concentration of polyisobutylene solution of preparation is 1～40 quality %, the concentration of relaxation reagent in polyisobutylene solution of adding be 1～100 mM/liter.Described internal standard compound is a tetramethylsilane, and relaxation reagent is chromium acetylacetonate or ferric acetyl acetonade, preferred chromium acetylacetonate.
The inventive method is used
13Magnetic field can be produced by electromagnet or superconducting magnet in the nuclear magnetic resonance spectrometer that the C-nuclear magnetic resonance spectroscopy uses, i.e. optional electricity consumption magnet type of nuclear magnetic resonance spectrometer or superconducting magnet type.
According to definition, the number-average molecular weight of polyisobutylene is tried to achieve by following formula,
Mn＝56×n
In the formula, Mn is the number-average molecular weight of polyisobutylene, and n is the degree of polymerization, and 56 is the pib molecule amount.
The polyisobutylene that is obtained by cationic polymerization comprises the active polyisobutylene that is obtained by pure isobutene polymerisation, the nonactive polyisobutylene that is obtained by the mixed c 4 olefinic polymerization, and the lower polyolefins of the two keys of remnants that obtain of other polymerizations.General polyisobutylene molecular structure has three types.First kind is α type polyisobutylene, has CH
2=CCH
3R type structure, shown in (I), characteristics be after the polymerization double bond position in the end of chain.Second kind is β type polyisobutylene, has (CH
3)
2C=CHR type structure, shown in (II), characteristics are that two keys have moved a carbon atom in chain, promptly double bond position is in the β position.The third is a T type polyisobutylene, characteristics be double bond position in chain, be that four hydrogen atoms that olefinic carbon is connected are all replaced by alkyl with double key carbon, shown in (III).Double-linked carbon goes out the peak position between δ 100～160ppm, as shown in Figure 1 in the dissimilar polyisobutylene in carbon spectrum; And its alkyl carbon atoms goes out the peak position between δ 0～70ppm, as shown in Figure 2.
The degree of polymerization of polyisobutylene can be tried to achieve with two key methods or methylene method according to nmr spectrum in the present invention (3) step.
The method of calculating the degree of polymerization with two key methods is: accurately measure in the alkane carbon district shown in Figure 1 and produce the total area at peak and the total area that two keypad olefinic carbon produces the peak by alkyl carbon, peak area is tried to achieve by integral method, is calculated the degree of polymerization of polyisobutylene again by formula (1),
N=1/2 (I
Saturated/ I
Two keys+ 1) (1)
In the formula (1), I
SaturatedBe alkane carbon district peak area summation, I
Two keysBe olefinic carbon district peak area summation.
The method of calculating the degree of polymerization with the methylene method is: accurately measure the total area at each peak, methylene district in the carbon spectrum and the area of α methylene peak, and by the degree of polymerization of formula (2) calculating polyisobutylene,
N=I
CH2/ I
α type CH2* α+1 (2)
In the formula (2), I
CH2Be methylene base (total area at δ 50～62ppm) each peak, I
α type CH2Be the area at α type methylene (δ 53.7ppm) peak, α is the molar content of α type polyisobutylene in the polyisobutylene.I
CH2, I
α type CH2Peak area by methylene base shown in Figure 2 is obtained.The alkane carbon district of polyisobutylene carbon spectrum shown in Figure 2 can be subdivided into three sub-regions: methylene base, quaternary carbon district and methyl district.The medium and small figure of Fig. 2 is a methylene base enlarged drawing, and wherein the reference peak of arrow indication is the α methylene peak, the peak that promptly adjacent with α type polyisobutylene chain terminal double bond methylene produces, the peak that other peak produces for other methylene.In the formula (2), the α value is tried to achieve by the two keypad peaks of Fig. 1, and in the little figure of Fig. 1, two peaks are the two keys of α type, promptly is positioned at the peak that two keys of link ends produce, this α type pair key peak areas and be the α value with the number percent of each peak total area of two keypads.
Further specify the present invention below by example, but the present invention is not limited to this.
Example 1
Get 0.20 gram polyisobutylene sample, in the 1.5 milliliters of sample bottles that can seal of packing into, add 0.5 milliliter of deuterochloroform (CDCl fast
3), shake up after sealing; This solution immigration has been equipped with in the Φ 5mm nuclear-magnetism sample hose of 10 milligrams of relaxation reagent chromium acetylacetonates; Add cap and seal with sealing tape.At room temperature, under the resonant frequency of 125.64MHz, record polyisobutylene with Varian INOVA500 type nuclear magnetic resonance analyser (production of Varian company)
13The C-nmr spectrum.With the number-average molecular weight of two key method working samples, see Table 1 with the correlation data of vapor-pressure osmometry (VGO) measurement result.
Example 2
The method of pressing example 1 is measured the polyisobutylene sample
13The C-nmr spectrum by the number-average molecular weight of methylene method working sample, sees Table 2 with the correlation data of vapor-pressure osmometry (VGO) measurement result.
Table 1
| The sample sequence number | Scanning times | ????I Saturated | ????I Two keys | ???? Mn | Mn (VPO method) |
| ????1 | ????3100 | ????71.0 | ????2.0 | ????1022 | ????999 |
| ????2 | ????12100 | ????164.0 | ????2.0 | ????2324 | ????2306 |
Table 2
| The sample sequence number | ?α，％ | ????I CH2 | ????I α type CH2 | ??? Mn | Mn (VPO method) |
| ????1 | ??63.3 | ????100.00 | ????3.96 | ????951 | ????999 |
| ????2 | ??83.8 | ????100.00 | ????1.89 | ????2539 | ????2306 |
Claims (8)
1, a kind of assay method of polyisobutylene molecular weight comprises the steps:
(1) the polyisobutylene sample be dissolved in make polyisobutylene solution in the deuterated reagent that contains internal standard compound, add relaxation reagent again and make testing sample,
(2) use
13The C-nuclear magnetic resonance spectroscopy is measured testing sample, obtains carbon spectrum spectrogram,
(3) peak area ratio of the peak area of the peak area by alkane carbon district in the carbon spectrogram and olefinic carbon district peak area ratio or methylene base and α methylene is tried to achieve the degree of polymerization of polyisobutylene, calculates molecular weight by the degree of polymerization again.
2, in accordance with the method for claim 1, it is characterized in that described deuterated reagent is selected from deuterochloroform or deuterium for benzene.
3, in accordance with the method for claim 1, it is characterized in that described internal standard compound is a tetramethylsilane.
4, in accordance with the method for claim 1, it is characterized in that described relaxation reagent is chromium acetylacetonate or ferric acetyl acetonade.
5, in accordance with the method for claim 1, the concentration that it is characterized in that described polyisobutylene solution is 1～40 quality %, the concentration of relaxation reagent in polyisobutylene solution be 1～100 mM/liter.
6, in accordance with the method for claim 1, it is characterized in that
13The spectrometer that the C-nuclear magnetic resonance spectroscopy adopts is electromagnetism swage or superconducting magnet type.
7, in accordance with the method for claim 1, it is characterized in that the degree of polymerization of polyisobutylene in (3) step is tried to achieve by formula (1),
1/2 (I
Saturated/ I
Two keys+ 1) (1)
In the formula (1), I
SaturatedBe alkane carbon district peak area summation, I
Two keysBe olefinic carbon district peak area summation.
8, in accordance with the method for claim 1, it is characterized in that the degree of polymerization of polyisobutylene in (3) step is tried to achieve by formula (2),
I
CH2/ I
α type CH2* α+1 (2)
In the formula (2), I
CH2Be the total area at each peak, methylene base, I
α type CH2Be the peak area of α methylene, α is the molar content of α type polyisobutylene in the polyisobutylene.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102539285A (en) * | 2011-12-31 | 2012-07-04 | 蓝星化工新材料股份有限公司江西星火有机硅厂 | Weight extrusion method for analyzing molecular weight of 110 methylvinyl silicone rubber |
| CN108152318A (en) * | 2017-12-22 | 2018-06-12 | 黄河三角洲京博化工研究院有限公司 | A kind of quantitative nuclear magnetic resonance hydrogen spectruming determining synthesis is to the method for conversion ratio in polyisobutene phenol process |
| CN108195869A (en) * | 2018-02-07 | 2018-06-22 | 广州天赐高新材料股份有限公司 | The detection method of guar hydroxypropyltrimonium ammonium chloride degree of substitution |
| CN110389147A (en) * | 2018-04-18 | 2019-10-29 | 中昊晨光化工研究院有限公司 | A method of structure and molecular weight based on nuclear magnetic resonance measuring perfluoropolyether |
-
2004
- 2004-01-19 CN CNB2004100009515A patent/CN100559174C/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102539285A (en) * | 2011-12-31 | 2012-07-04 | 蓝星化工新材料股份有限公司江西星火有机硅厂 | Weight extrusion method for analyzing molecular weight of 110 methylvinyl silicone rubber |
| CN102539285B (en) * | 2011-12-31 | 2014-08-27 | 蓝星化工新材料股份有限公司江西星火有机硅厂 | Weight extrusion method for analyzing molecular weight of 110 methylvinyl silicone rubber |
| CN108152318A (en) * | 2017-12-22 | 2018-06-12 | 黄河三角洲京博化工研究院有限公司 | A kind of quantitative nuclear magnetic resonance hydrogen spectruming determining synthesis is to the method for conversion ratio in polyisobutene phenol process |
| CN108152318B (en) * | 2017-12-22 | 2020-07-31 | 黄河三角洲京博化工研究院有限公司 | Method for measuring conversion rate in process of synthesizing p-polyisobutylene phenol by quantitative nuclear magnetic resonance hydrogen spectrum |
| CN108195869A (en) * | 2018-02-07 | 2018-06-22 | 广州天赐高新材料股份有限公司 | The detection method of guar hydroxypropyltrimonium ammonium chloride degree of substitution |
| CN110389147A (en) * | 2018-04-18 | 2019-10-29 | 中昊晨光化工研究院有限公司 | A method of structure and molecular weight based on nuclear magnetic resonance measuring perfluoropolyether |
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| Publication number | Publication date |
|---|---|
| CN100559174C (en) | 2009-11-11 |
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